This invention relates to pre-crash warning systems for road vehicles. More particularly, it relates to a system for robustly assessing the expected severity of an impending crash of two vehicles.
In currently-available pre-crash warning systems for road vehicles, the safety benefits are limited because such systems do not provide sufficient information about the object in the path of the vehicle to reliably predict the severity of an imminent crash. For example, currently-available systems cannot distinguish between two vehicles which are about the same size but which have significantly different mass and hence have critically different crash characteristics. Consequently, the safety benefits of such pre-crash warning systems are limited to (1) pre-arming of non-resettable devices, such as airbags, so that they can be deployed more rapidly in cases where the subsequent collision is sufficiently severe to warrant deployment, and (2) triggering non-aggressive resettable safety devices that do not interfere with the vehicle driving function, such as extendible/retractable bumpers and extendible/retractable knee bolster systems. There is a need for pre-crash warning systems which not only give warning of an imminent crash but also predict the severity of the crash.
In the prior art, the Sekine U.S. Pat. No. 5,546,311 granted Aug. 13, 1996 describes an intercommunication system for vehicles which supplies speed and direction information for the purpose of collision avoidance.
Other prior art patents relating to collision avoidance systems are Blowney et al U.S. Pat. No. 3,097,354 granted Jul. 9, 1963; Gilon et al U.S. Pat. No. 5,684,474 granted Nov. 4, 1997 and Giovanni U.S. Pat. No. 5,841,367 granted Nov. 24, 1998.
The known prior art does not disclose a system for exchanging critical vehicle crash-defining information between two vehicles in an imminent crash situation, predicting the severity of the crash and controlling occupant protection devices in accordance with the prediction.
In accordance with this invention, a system is provided which predicts the severity of an imminent collision of two vehicles based upon robust crash-defining information about both vehicles.
Further, in accordance with the invention, the robust crash-defining information about both vehicles is developed after the collision becomes inevitable and imminent. Further, the prediction of crash severity is developed in time so that occupant safety devices can be deployed in accordance with the predicted crash severity.
Further, in accordance with this invention, road vehicles are provided with pre-crash warning systems with automatic means for exchanging critical vehicle crash information between two vehicles when a collision between the two vehicles is determined to be inevitable and imminent. The critical information is used to deploy non-reversible and reversible safety systems when a collision is imminent.
Further, in accordance with this invention, a method of predicting the severity of an imminent collision of two vehicles is provided whereby occupant protection devices of the vehicles may be deployed in accordance with the predicted severity. The method comprises the steps of determining that a collision of the vehicles is imminent, exchanging vehicle crash-related information between the vehicles, computing crash-defining information onboard each vehicle based upon the crash-related information and predicting onboard each vehicle the severity of the imminent collision based upon the computed crash-defining information.
Further, in accordance with this invention, apparatus for use onboard a road vehicle is provided for predicting the severity of an imminent collision and for controlling deployment of occupant protection devices in accordance with the prediction. The apparatus comprises means for determining whether the vehicle is closing on another vehicle and for producing a warning signal when a collision of the two vehicles is imminent, means responsive to the warning signal for transmitting crash-related information to the other vehicle, means for receiving crash-related information from the other vehicle, and computer means for processing said crash-related information from both vehicles and for predicting the severity of the collision, whereby the occupant protection devices may be deployed in accordance with the severity.
Further, in accordance with this invention, the critical information is exchanged between the two vehicles by means such as electromagnetic, optical or ultrasonic systems. Alternatively, the critical information is exchanged by use of satellite-based systems or by use of radio transceiver or transponder systems.
A complete understanding of this invention may be obtained from the detailed description that follows taken with the accompanying drawings.